stack

Fabricio: Docker stack

This example shows how to deploy Docker stack consisting of a single service based on official Nginx image.

Requirements

• Fabricio 0.4.2 or greater
• Vagrant
• One from the list of Vagrant supported providers (this example was tested with VirtualBox)

Files

• fabfile.py, Fabricio configuration
• docker-compose.yml, Docker Compose configuration file
• README.md, this file
• Vagrantfile, Vagrant config

Virtual Machines creation

Run vagrant up and wait until VMs will be created.

List of available commands

fab --list

Deploy

Before proceed you have to initialize Docker swarm cluster by running following command:

fab swarm-init

Note: use fab swarm-reset to reset cluster

After cluster has been successfully initialized everything is ready to work with stacks:

fab stack

Deploy idempotency

Fabricio tries to deploy stack either if content of provided Docker Compose configuration file was changed or any image of stack services has newer version since last successful deploy attempt. However stack deploy can be forced by using force flag:

fab stack:force=yes

Parallel execution

Any Fabricio command can be executed in parallel mode. This mode provides advantages when you have more then one host to deploy to. Use --parallel option if you want to run command on all hosts simultaneously:

fab --parallel stack

Rollback

Try to update your docker-compose.yml and run deploy again:

fab stack

This will update stack using new compose configuration. After that you can return stack to previous state by running 'rollback' command:

fab stack.rollback

Customization

See also "Hello World" Customization section.

Custom docker-compose.yml

Custom docker-compose.yml can be provided using compose-file option:

from fabricio import docker, tasks

stack = tasks.DockerTasks(
    service=docker.Stack(
        name='my-stack',
        options={
            'compose-file': 'custom-docker-compose.yml',
        },
    ),
)

compose-file option (as well as any other option) can be a callable taking docker.Stack instance as parameter:

from fabric import api as fab
from fabricio import docker, tasks

def compose_file(
    stack,  # type: docker.Stack
):
    # select compose file depending on infrastructure name
    # (see 'Infrastructures and roles' example)
    return '%s-compose.yml' % (fab.env.infrastructure or 'default')

stack = tasks.DockerTasks(
    service=docker.Stack(
        name='my-stack',
        options={
            'compose-file': compose_file,
        },
    ),
)

Orchestrator select

Since Docker 17.12.0-CE (for Mac/Windows) it is possible to choose orchestrator for cluster by setting DOCKER_ORCHESTRATOR environment variable. In the example below Docker forced to use kubernetes orchestrator instead of default one:

from fabricio import docker, tasks

stack = tasks.DockerTasks(
    service=docker.Stack(
        name='k8s-stack',
        options={
            'compose-file': 'docker-compose.yml',
        },
    ),
    env={
        'DOCKER_ORCHESTRATOR': 'kubernetes',
    },
)

Note: env parameter became available from Fabricio 0.5.5